Refractory heat insulation



April 27, 1937. F. cHRlsTENsON ET A1.

REFRAc'foRY HEAT INSULATION Filed Aug. 22, 1936 INVEN TOR S fsw/szwsa/V 90E Af. (Z0/Pff J ATTORN EVS Patented Apr. 27, 1937 PATENT oFFlcE REFRACTORY HEAT INSULATION Frank Christenson, Jamaica, N. Y., and Horace N. Clark, Bound Brook, N. J.

Application August 22, 1936, Serial No. 97,414 5 Claims. (Cl. 'i2-16) This invention relates to heat insulation for use in lining flues, furnace walls and the like which are subjected to high temperatures.

An object of the invention is to provide an eflicient, durable and economical insulation for the above purpose.

Another object is to provide a. heat insulating lining which may be readily applied and built up in the field.

Another object is to heat insulating tory surface.

Various other objects and advantages will be apparent as the nature of the invention is more fully disclosed.

Although the invention is capable of various uses, it will be understood from the following provide a wall having properties and having a refracdescription and the accompanying drawing, in

which a specific embodiment thereof is set forth for purposes of illustration.

In the drawing:

Fig. 1 is a transverse section of a portion of a wall showing the heat insulation applied thereto; and

Fig. 2 is a broken perspective view showing the details of construction.

Referring to the drawing, the invention is shown as applied to a portion of a wall I0 of a iiue'or the like which is adapted to carry gases, as for example from a furnace to a stack. This wall I0 is made of thin sheet metal and is.pro vided with a plurality of pins II and I2 which are welded or otherwise secured to the inner surface thereof and act as securing means for the heat insulation to be described.

The pin I I is shown as a split pin havingpoints adapted to be bent over to hold the insulation whereas the pin I2 is shown as a shank adapted to extend through the lining and secure the same by a washer I3 and a cotter pin I4. It is to be understood that the pins may be all of the same type or that other means for securing the insulation to the walls may be used. The 'pinsjhave been shown for purposes of illustration only.

The heat insulation comprises a layer I5 of fibrous insulating material, such as mineral wool, asbestos or the like, held between expanded metal vscreens I6 and I1 which are joined together by transverse Wires I8 passing through the material I 5 and rmly securing the screens to the opposite sides thereof. A layer of waterproof paper I9, for example, asbestos paper,- may be positioned between the screen I1 and the material I5 to cover the exposed face of the insulating material and to external moisture.

The layer of fibrous insulating material held between the screens I 6 and I1 constitutes a blanket which is suiciently iiexible to readily conform to the surface of a wall and possesses enough rigidity to facilitate handling. It is preferably made under pressure so that the bres are compacted into a comparatively dense layer.

This blanket is used to line the Walls I0 with the screen I1 and moisture-proof paper I 9 exposed so that the fibres are protected thereby.. It may be applied over the pins I I and I2 and forced against the wall I 0, causing the pins to penetrate the material I5 and the paper I9 and to extend beyond the screen I1. 'Ihe blanket is held in position by bending over the joints of the split pin II and by the Washer I3 and cotter pin I4 on the pin I2.

The exposed surface of the blanket is then covered with a layer 20 of castable monolithic refractory cement which adheres to the screen I'I and forms a monolithic refractory facing over the entire surface. The layer I9 of waterproof paper prevents the moisture from this refractory cement from entering the brous insulating material while the cement is setting.

In certain instances, layer I9 may be made of combustible material, in which case it will burn out after the wall has been completed and is protect the same from subjected to high temperatures, leaving the insulating blanket in contact with the wire screen I1. Inasmuch as the cement before the Wall is subjected to high temperature, the water proof paper is no longer required for protecting the bres-and the burning out of the same will accordingly not affect the heat insulating properties of the wall.

The structure above described provides a fibrous blanket having high heat insulating properties, which is faced with a hard refractory material capable of preventing physical injury to the fibres. The structure is durable and at the same time may be readily applied to walls of different shapes. The insulating blanket can be readily cut and positioned on the wall and, when covered with the layer of refractory cement, provides a permanent and efficient heat insulating structure.

It is to be understood that this structure may be applied to furnace walls, to hot air ducts and to various other locations in which it is desired to conserve the heat and to prevent injury to a wall by hat gases. A furnace'wall may be made in this manner at a saving in cost because the outer Wall i@ is not required to withstand intense heat and may be made of comparatively light ma- 'terial.

`Although a certain embodiment of the invention has been described for purposes of illustra tion, it is to be understood that various changes and modications may be made therein without departing from the scope of the invention, which is to be limited only in accordance with the following claims when interpreted in View oi the prior art.

What is claimed is:

1. A heat insulating wall comprising a blanket of insulating material having a facing of castable monolithic refractory cement, said blanket comprising a layer of fibrous heat insulating material supported between metal screens.

2. A heat insulating wall comprising a blanket 20 of insulating material formed by a layer of fibrous heat insulating material held between metal screens and a layer of castable monolithic refractory cement covering the face of said blanket and attached to one of said screens.

3. A heat insulating wall comprising a pair of metal screens having a layer of fibrous insulating material positioned therebetween, means eX- tending between said screens and through said insulating material for securing the same'to form a comparatively rigid blanket, a layer of waterproof paper under one of said screens to cover the exposed face of the insulating material, and a facing of castable monolithic refractory cement covering said exposed face of the blanket and secured to said last screen.

4. A heat insulating wall comprising a sheet metal wall lined by a blanket formed of a layer of brous heat insulating material held between metal screens', pins extending through said blanket to secure the same to said sheet metal wall, and a facing of castable monolithic refractory cement over the exposed face of said blanket.

5. The method of making a heat insulating Wall which comprises lining a metal wall With a blanket of brous heat insulating material having its exposed face covered by a layer of paper and held by a metal screen, covering the metal screen with a layer of castable monolithic refractory cement, allowing the cement to set, and then burning out the paper to form a rigid wall composed entirely of refractory material.

FRANK CHRISTENSON. HORACE N. CLARK. 

